adding vertex custom data for game engine shaders
I was aware of using vertex colors and I have used them in the past for vertex animations. 
But as there was a need for 3 different data properties I didn't know how to represent the extra detail in the vertex.

I started looking for my answer from the perspective of the shader instead of blender + custom vertex data.

fortnite procedural animation

What this developer did was use a additional UV channel instead.